1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Angle between curve and sphere

  1. Jul 21, 2011 #1
    I need to find the angle between a curve x^2 + y^2 =1, z = sqrt(2)x/y and a sphere z^2 + y^2 + z^2 = 1. I found two points of intersection, (0,1,0) and (0,-1,0), so at each of these points I assume that there's a tangent line to the curve and a tangent plane to the sphere. Then I'm guessing I'd find the angle between the direction vector of the tangent line to the curve and the normal vector of the tangent plane. Am I on the right track?

    I have the direction vector of the tangent line to the curve at (0,1,0) as <1, 0, sqrt(2)> and at (0,-1,0) as <-1,0,-sqrt(2)>. I'm not sure where to go from here.
     
  2. jcsd
  3. Jul 21, 2011 #2

    micromass

    User Avatar
    Staff Emeritus
    Science Advisor
    Education Advisor
    2016 Award

    Yes, that's good.

    Well, find the tangent plane to the sphere at the points (0,1,0) and (0,-1,0).
     
  4. Jul 21, 2011 #3
    Oh, so that'll just be a 90 degree angle in both cases, since <+-1, 0, +-sqrt(2)>.<0,+-2,0> = 0 so arccos0 = pi/2.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook